[Early diagnosis of heterotopic pregnancy with viability of the intrauterine fetus. Report of two cases and review of the literature].

Heterotopic pregnancy, or coexistence of intrauterine and extrauterine pregnancy, is a rare entity, with a difficult pre-operative diagnosis, and potentially dangerous for the mother and for the intrauterine pregnancy. There are risk factors that are increased by this entity, so it should be taken into consideration if assisted reproduction techniques are used. The use of ultrasonography and laparoscopy is fundamental for detection, in order to implant an opportune treatment. Two cases of heterotopic pregnancy with viability of intrauterine gestation, are presented.